ABSTRACT
The rediscovery of Mendel's laws of heredity in the beginning of the 19th century had its impact, and the genetics of the host and the pathogen attracted attention of plant pathologists. It is the phenomenon that a plant, once appropriately stimulated, exhibits an enhanced systemic resistance subsequently to a broad spectrum of challenging pathogens. In an attempt to escape the rust disease, coffee production moved to the western hemisphere. Waterhouse saw the need to intensify this work in the north-western part of New South Wales, where rust was a serious problem and began testing there. Big bud of tomato (TBB) was first described in 1933 AD as a virus disease and affected plants were reported as having a dense, tufted habit with an enlarged bladder-like calyx. A serious fungal disease in Africa is Fusarium wilt or Panama disease, which attacks the roots of the banana plant, affecting the vascular system required for mineral and water transport.
